England hooker Dylan Hartley is set to have knee surgery on Tuesday that will rule him out of the rest of the Six Nations.
“Dylan went to see the surgeon and they felt in conjunction with our medical people the progress was a bit slow,” Chris Boyd was quoted as saying by the Northampton Chronicle.
“He’s going to have a surgical procedure on Tuesday to open it up and see what’s causing the knee to be grumbly. Depending on what they find, it will depend on how long his rehab will be.
“If it went outstandingly well, he could be playing in four weeks but if it’s something a bit more problematic it might be a bit longer.”